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Re: [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type

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On Wed, Aug 9, 2017 at 3:26 PM, David Howells <dhowells@redhat.com> wrote:
> Arnd Bergmann <arnd@arndb.de> wrote:
>
>> Do you know which format is used in practice? Are both kad and k5 common
>> among rxrpc users?
>
> The aklog program I'm using uses the non-XDR interface to push a Kerberos 5
> ticket to the kernel, so it doesn't actually invoke rxrpc_preparse_xdr() from
> rxrpc_preparse().

Ah, I'm slowly starting to understand how this fits together. So you can add
a key either through key_add() from local user space, or through an rxrpc
socket.

From what I can tell, the program you have at
http://people.redhat.com/~dhowells/rxrpc/klog.c will keep working beyond
2038 but not beyond 2106 on all 64-bit architectures and on those
32-bit systems that have a libc with 64-bit time_t. It could be modified
to use the xdr_rxk5 key format, which would make it use 64-bit time
values (and require the kernel fix mentioned above).

In contrast, the rxrpc socket interface would need a major rework to
support 64-bit expiration times. It receives a kerberos ticket with a
32-bit issue time
that gets used to calculate the expiry time in rxkad_decrypt_ticket, and from
there we pass it through a  rxrpc_key_data_v1 into key_instantiate_and_link(),
which calls rxrpc_preparse() and that just takes the expiry out again and sticks
it into another 32-bit field in struct rxkad_key, from where it
finally gets copied
into the (now 64-bit) key_preparsed_payload->expiry field.

Does my understanding match what you intended for the interfaces? Is there
a need to extend the rxrpc socket interface to support xdr_rxk5 keys as well?

         Arnd

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[PATCH 0/3] Fix y2038 issues for security/keys subsystem Baolin Wang <baolin.wang@linaro.org> - 2017-08-09 05:00 +0200
  [PATCH 2/3] security: keys: Replace time_t with time64_t for struct key_preparsed_payload Baolin Wang <baolin.wang@linaro.org> - 2017-08-09 05:00 +0200
  [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type Baolin Wang <baolin.wang@linaro.org> - 2017-08-09 05:00 +0200
    Re: [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type Arnd Bergmann <arnd@arndb.de> - 2017-08-09 11:10 +0200
      Re: [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type David Howells <dhowells@redhat.com> - 2017-08-09 11:40 +0200
        Re: [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type Arnd Bergmann <arnd@arndb.de> - 2017-08-09 12:10 +0200
          Re: [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type David Howells <dhowells@redhat.com> - 2017-08-09 15:30 +0200
            Re: [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type Arnd Bergmann <arnd@arndb.de> - 2017-08-09 17:20 +0200
              Re: [PATCH 3/3] net: rxrpc: Replace time_t type with time64_t type David Howells <dhowells@redhat.com> - 2017-08-09 17:50 +0200
  [PATCH 1/3] security: keys: Replace time_t/timespec with time64_t Baolin Wang <baolin.wang@linaro.org> - 2017-08-09 05:00 +0200
  Re: [PATCH 0/3] Fix y2038 issues for security/keys subsystem David Howells <dhowells@redhat.com> - 2017-08-09 10:30 +0200
    Re: [PATCH 0/3] Fix y2038 issues for security/keys subsystem Baolin Wang <baolin.wang@linaro.org> - 2017-08-10 04:10 +0200
  Re: [PATCH 0/3] Fix y2038 issues for security/keys subsystem Arnd Bergmann <arnd@arndb.de> - 2017-08-09 10:50 +0200
    Re: [PATCH 0/3] Fix y2038 issues for security/keys subsystem Baolin Wang <baolin.wang@linaro.org> - 2017-08-10 04:10 +0200

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